Updated description by mtbgreg1, circa 2010:
Detailing one specific route at Big Creek is impossible. I will cover the area in detail below and attempt to include directional information as I do so, but it will be up to you to choose the best route after that. Don't worry, the trail signage is very thorough and will be sufficient to keep you from getting too turned around.
Cross Country Mountain Biking
The 6 or so miles of cross-country oriented singletrack trails of Big Creek are well-maintained, well-marked, and entertaining to ride. The trails are labeled with different colors based on their level of technical difficulty, so its easy to pick the trail that will serve your needs the best.
The black/advanced trails feature plenty of rocks, some log rides and other features, a few stiff climbs, and a couple of drop offs.
Most of the trails are directional, so check the signs and pay attention to what day of the week it is!
Downhill
While the cross-country trails are pretty cool, Big Creek's true claim to Atlanta area fame are its downhill and dirt jump-oriented trails. From what I hear, there is really no other place in Atlanta with this kind of riding, and possibly only 1 other place in the state of Georgia with downhill-specific trails! There are about 5-7 different trails to choose from packed tightly together on a hill side located about a mile down the greenway. There are also a number of rock drops spread throughout the area, with 4 or so on the backside of the upper ridge dropping down towards a maintained park.
I've ridden my All Mountain bike down many of these trails before, and I've heard people say that they really don't live up to true downhill-oriented trails. While that may be true, I know that I definitely don't feel comfortable on a 5" travel bike bike when:
pinning it (that means going completely balls-out high-speed for those not familiar with moto lingo) through the rock gardens containing mini boulders and 3 foot drops after many of the rocks
sending a 3 foot high booter to a super long landing (where you could get as much air as you want)
airing a 15 ft long table top
doing various rock drops ranging from 4ish feet to 7-8 feet
Bearing in mind that these trails are located in Atlanta, I'd say the terrain is pretty freaking sweet!
Dirt Jumps
Big Creek has a dedicated line of high-quality purpose-built dirt jumps that run along the top of the ridge above the other downhill and freeride runs. There are a mix of different size jumps ranging from relatively small to one with a lip that's pushing 6 feet high or more. To the best of my knowledge, there is nowhere else in Atlanta, or even the state of Georgia for that matter, with an area that even comes close to comparing to the near-professional grade of these jumps. While most of the riders I have seen sessiong them have been on dirt-jumping mountain bike frames, I've witnessed a number of BMXers sending it big time as well.
Slalom Course
Located directly in the center of all of the action, the banked slalom-type course seems to be the focal point of all the attention. It is appropriate that all the other trails seem to be built around it, as riders of all different disciplines can navigate the slalom run. For instance, when I was last out at Big Creek, I saw a kid on a rigid single speed 29er rolling down through the berms.
So granted, the big berms and flow are going to be accessible to anyone on almost any bike. To really rail this trail and air out the big table tops, however, you're going to need to be riding something much more aggressive than a rigid SS 29er. A dirt jump bike would be perfect for this kind of work, and a BMX bike or a downhill bike would also function passably, despite being on opposite ends of the bicycle-size spectrum.
Pumptrack
One of the newest additions to Big Creek is a pumptrack with beginner and advanced lines. Come here to get your first taste of rollers and berms, or to rack the speed up and get your flow on!
Night Riding:
Night riding at specific times, with approved leaders only.
 | Climbing Snake |  | 1.2 mi |
| Hurts So Good | | 0.7 mi |
| Pine Hill | | 0.6 mi |
 | Troll Trail |  | 0.3 mi |
Troll trail is a cross country tech trail filled with great features with ride arounds. A small north shore skinny ends the trail which is sure to bring thrills all in all good place to warm up for advanced riders
| ThankThe singletrack is nice but what you really go here for is the downhill section. There's a bunch of fun lines back there with lots of jumps, table tops, berms, ect. There's at least on significant drop off and a cool run down a dry creek bed.
| ThankDirection link is wrong. Use 1600 Old Alabama Rd to find car park. If you like roots, rocks & tight turns you will love this trail. Good to improve anyone's techincal riding. This is intermediate to advanced...really great fun 5 mile trail.
| ThankI only rode Stumpy's loop. I was looking for a step up from Mosquito Bite to prepare for the Dwelling loop. On paper this trail didn't look to difficult, but the climb seems to happen all at once and it got pretty steep as I rode counterclockwise (walked twice, I wasn't prepared to go up some of the root steps). Trail surface was roots, rocks, more roots, more rocks, a few bridges, and a little dirt. I will be riding this trail again.
| ThankThe freeride area is the focal point of the park. XC trails are well-maintained but haven't been significantly updated in many years. No open sections, all singletrack and not very much flow or fast sections. They're really rocky, rooty and climby. Great for strength/technical training, but it's pretty hard to do a lot of miles here.
| ThankSo close to home and for that I like it, but the XC trails are just meh. Tree roots everywhere and it just feels like you are winding around and not really going anywhere. Beggers can't be choosers so, I still use it and have a good time nonetheless. I've ridden my hardtail 29er on the free ride section and it's fun, but short. 700 to 1000 ft runs or something like that. I'm on the wrong bike to really do it justice, plus the skills and courage to really push it aren't there anymore. The XC trails can get quite busy on the weekend, come early.
| ThankI love the trails here.
| Thankvuggin rad brah. head straight to the free ride section and get sendy
| ThankWhen you get here, ignore the XC trails and go straight to the freeride section. park in the lower lot and ride the greenway for a mile or so and exit right at the doggy poop station. It is a little gravel entrance. Then ride. The freeride section is seven or eight trails, but I could ride these for hours. If you are just learning to mountain bike, try blankets first (especially for XC). If you ride every weekend and like freeride, this is the place for you.
Freeride Trails:
Gully: a long trench with some small takeoffs and nice berms. Ride fast in this stuff.
Lunch line: A collection of rock gardens and mini drops. Fun and good practice for races.
Slalom: Easiest trail, nice berms and two tabletops. Can rail this trail if desired.
Hawkeye: Not well maintained at all, kinda raw, but still fun.
Honor roll: Tons of berms and a toilet bowl 180
feature
Sender row: 3 ft launcher drop to downslope. Get speed and fly!!
El schorcho: Old XC trail now a Dh run descend 200 vertical feet in 700 feet of trail. Steep sharp switchbacks.
Typhoon: 7ft rock drop and wood bridge gap
Drit jumps: 3 lines, fun, more fun, really fun
Elevator: Uphill trail, but does have a rock drop if you go the other way. Not sure if It's allowed though.
Wear a helmet, hands of the brakes, and have fun!
| ThankI though the same thing as you when I came here, but that time I only rode the XC trails. Those are bad. The next time I went to the freeride park, and it is very fun. There is a multitude of trails, but probably isn't a good place to learn to jump. For that I recommend blankets, rope, or allatoona. Very fun trails overall. To get to the Dh park follow the green about a mile, and you will see it on your right next to a dog poop bag dispenser.
| ThankThis is a fantastic trail. I live extremely close to the trail, just as it is extremely close to my heart. Some of the greatest memories with my father were here, when he and I would could out here during the off season back when I used to race BMX and ride almost weekly. It has progressed a lot since I first started riding here god knows how long ago. At first it was just trails, but now it is something more than that. It has a pump track, multiple downhill routes with jumps and sharp, fast turns, and trails ranging from beginner to expert. No matter the skill level there is a trail for you.
| ThankBig Creek has a special place within my heart. This was the first great trail I came to. It was also where I learned to ride downhill trails on my sketchy 29er XC bike. Two years later I can say that I still love the place. The trails are good and well maintained, but not as good as Blanket's Creek. The downhill section is the best though. They are always building and making the runs better. While there is nothing too gnarly in the section, it always provides a great time on my bike.
| ThankFun little trail, but it was hard to follow and certain times. It is two miles from my sisters so I will be hitting it anytime I visit as I did enjoy the trail a lot. Some decent little climbs made it fun!
| ThankNice flow over the roots & rocks. Nice features on the downhill trails.
Singletrack's directions are incorrect.
| ThankCorrect address is: 1805-1809 Old Alabama Rd, Roswell, GA
The front section is fun and fast, but the closer you get to the freeride section the tougher it gets.
| ThankMy first ride on my new 29er! It was a pretty cool ride. Kind of rough, roots and rocks, but overall a fun ride. Not to steep, uphill or downhill.
| ThankPerferct after work or quick weekend ride. You won't find better maintained or better marked trails anywhere. This is a wonderful place to try mountain biking for the first time or perfect conditioning ride for the pros. Can get a little cnogested but that's only because of how accessible it is. Lots of bang for the buck.
| ThankPerfect for Beginner, Intermediate and Pro Riders. Everybody has it's own section. As a beginner you choose a quick round and are back to your starting point in around 20 minutes. As an Intermediate, you just combine 2 or 3 of the well marked trails and you can go on for an hour and a half easily. Or you just take the same trail multiple times and get more and more familiar to it every time you ride it and can push a bit more every time. Even the beginner trail has some nice features like small jumps and balance beams, but no worries, these are all optional and you can just drive around them. Also a very big plus is that hikers and bikers are separated.
| ThankI've been mountain biking now for over 25 years, and I am the type who puts in the miles and rides more toward the aggressive side of things. I used to ride in the old trails here before development came in and cut the system in half. Kudos to the City of Roswell and RAMBO for salvaging what was left of some fun trails. However, aside from the free ride area (that survived from the old trails), the XC trails are not much to talk about. The XC trails lack any flow what so ever. The trails twist back and forth to make for more mileage, but steal every bit of momentum in doing so. If your local to the area, then these trails are good for exercise, but don't go out of your way travel here unless free ride is your thing. The XC trails really offer nothing in the way of good riding, maybe if they were bench cut and bermed up a bit to get more flow going.
| ThankThe trails are really well marked so I always knew where I was. Even though Stumpy's Loop is marked as a beginner trail, as a beginner myself, I felt it was very difficult and had to stop a few times. There are a lot of roots and rocks that added to the challenge.
| Thank